1. Field of the Invention
The present invention relates to an electronic device which eliminates all the factors that prevent a reduction in the thickness of the electronic device resulting from the use of an externally mounting type battery, and which has a display portion capable of being opened and closed with respect to its body by more than 180 degrees. The present invention also relates to a battery for this type of electronic device.
2. Description of the Related Art
In recent years, many portable electronic devices incorporating a central processing unit (CPU), such as notebook personal computers and mobile computers, have been made commercially available. In such electronic devices, the CPU is driven at a high clock frequency, so that a large amount of electrical power is consumed at the CPU, as a result of which electrical power consumption is concentrated at the CPU. Consequently, such electronic devices require a means for efficiently dissipating the heat of the CPU outside the CPU.
In general, portable electronic devices, such as notebook personal computers, comprise a body and a display portion. The display portion can be opened and closed with respect to the body through hinges.
Opening-and-closing structures, such as those shown in FIGS. 19 and 20, have conventionally been known as being used in notebook personal computers or the like in order to openably and closably support the display portion with respect to the body.
In the conventionally known opening-and-closing structure of FIG. 19, a liquid crystal display 1002 is openably and closably mounted to a body 1000 through a hinge 1001. In addition, a built-in type battery pack 1003 is accommodated in the body 1000.
On the other hand, in the conventionally known opening-and-closing structure of FIG. 20, a display 2001 is openably and closably mounted to a body 2000 through a hinge mechanism 2002. In addition, an externally mounting type battery pack 2003 is mounted to the rear end of the body 2000 in order to supply electrical power to the body 2000.
However, the structure of FIG. 19 has the following problems. Since the shaft of the hinge 1001 is disposed in the back edge 1004 of the thin, panel-shaped liquid crystal display 1002, the diameter of the hinge 1001 must be made smaller than the thickness of the liquid crystal display 1002. This prevents the hinge 1001 from having sufficient mechanical durability and strength. In addition, since the space for passing a signal wire from the body 1000 towards the liquid crystal display 1002 is small, an expensive flexible cable must be used as signal wire.
Further, in this structure, the rear end 1004 of the liquid crystal display 1002 is folded on top of the battery pack consisting of a plurality of batteries 1003A arranged in a row. Therefore, this structure is a layered type structure whose overall thickness cannot be reduced.
The structure of FIG. 20 has the following problems. Since the hinge mechanism 2002 and the battery pack 2003 are not coaxially disposed, a portion, with a thickness R1, for coupling the display 2001 and the hinge 2002 together must be provided. This means that the overall thickness of the portable personal computer is equal to the sum of thickness R1 of the coupling portion and the outside thickness R2 of the externally mounting type battery pack 2003. Consequently, the coupling portion with thickness Rl prevents the overall thickness of the portable personal computer from being reduced.
In the structure of FIG. 20, the presence of the battery pack 2003 limits the opening and closing range of the display 2001 to less than 180 degrees.